I dunno, I test drove a 97 LT1 M6, a 97 LT1 A4, and my 99 LS1 A4 at the ripe age of 19 by myself, just had to prove insurance... I actually remember my buddy test drove a 2001 LS1 Trans-Am a while ago (3 of us total, (18, 17 and 17)) and they let us go by ourselves, the oldest was driving, just needed proof of insurance.